1. Field of the Invention
This invention relates to a dot matrix printer for printing characters, symbols or the like constituted by dots, and more particularly to a dot matrix printer capable of varying the printing size of the characters, symbols or the like.
2. Description of the Prior Art
Dot matrix printers have generally effected single character size printing. Where printing at two or more different character sizes has been desired, one dot pitch has not been varied but the number of dots used in one character has been varied that is, the character font has been varied to change the character size. Therefore, the character size has been limited to the sizes such as 1/2 or twice the basic size for which the character font can be made by subjecting a character generator of the basic character pattern to a simple processing. Also, where characters of the other sizes have been desired, it has been necessary to prepare character generators for special size characters in addition to the character generator of the basic size. There is a method comprising varying the amount of feed of the printing head to vary the character size, but this method has required the feeding mechanism to be provided with a complex mechanism such as a speed change gear or a clutch and therefore has rarely been put into practical use from the viewpoints of reliability and cost.